US2444495A

US2444495A - Tappet-actuating member

Info

Publication number: US2444495A
Application number: US663082A
Authority: US
Inventors: Chase Alvin
Original assignee: Bristol Co
Current assignee: Bristol Co
Priority date: 1946-04-18
Filing date: 1946-04-18
Publication date: 1948-07-06
Anticipated expiration: 1965-07-06

Description

y 6, 1943- A. CHASE I TAPPET-ACTUATING MEMBER Filed April 18, 1946,

INVENTOR Al. vnv CHASE A TTORNEY 4 Patented July 6, 1948 TAPPET-AGTUATING MEMBER Alvin Chase, Waterbury, Conm, assignor to The Bristol Company, Waterbury, Conn., a corporation of Connecticut Application April 18, 1946, Serial No. 663,082

13 Claims. (Cl. 74-568) This invention relates to cam members such as may be utilized in process time cycle controllers, and more especially to means for operating a valve or switch, or equivalent control element in a cycle controller of the cam-actuated type wherein it is required that said valve or switch or equivalent be abruptly set in either of two significant positions at any preselected instant in the time-range of the controller. The art in process cycle controllers of the class in which the present invention lies is well exemplified in the co-pending application Serial No. 375,097 for improvements in process cycle controllers, filed January 21, 1941 by Harold E. Allen, now Patent No. 2,442,835, and assigned to the assignee of the applicant for patent covering the present invention.

The control instrument set forth and claimed in said H. E. Allen application includes a plurality of pilot valves adapted for abrupt opening or closing at preselected instants in a cycle of operation by means of corresponding cam members carried on a common shaft, together with means for advancing said shaft in such a manner that as the time cycle progresses said valves will be operatively engaged or disengaged by suitable conformed portions of the peripheries of said cam members. As shown in said appli-- cation, each of the cam members is formed with peripheral portions having either of two definite radius values, and as the valve actuating element is engaged thereby it will assume an open or closed position according to which of said portionsparticipates in said engagement.

An important attribute of process cycle controllers lies in flexibility of timing adjustment, and the ease and expediency with which adjustment may be effected. In the instrument set forth in said Allen application, the cams are characterized by having their eripheral profiles definitely formed before assembly; and, while by the use of a laminated construction there may be.

made possible a certain degree of flexibility in adjustment, complete adjustability requires a variety of types and forms of cam elements, involving a considerable number of spares, some of which will at all times be idle, together with the assembly problem attendant upon removing certain elements and replacing them by others.

It is an object of the present invention to provide a combination of a quick-acting control with an actuating cam member capable of infinite adjustment, with a minimum number of parts, and without the need for spares.

It is a further object to provide a cam member of this nature in which means for determining the opening and the closing events in the controlled cycle may be independently and noninterferingly set each at any desired point on the periphery.

' It is a further object to provide a cam member of the aforesaid nature in which any desired number of alternate opening and closing events may be adjustably and non-interferingly grouped upon a single cam. It is a further object to provide an adjustable cam member of the aforesaid nature which shall be at once rugged in construction, inexpensive to manufacture, and not subject to accidental displacement of active parts, with con-sequent shifting of the time setting, or interference with the pre-established cycle.

In carrying out the purposes of the invention, it is proposed to provide in combination with valve or equivalent control means adapted to actuation by means of a tappet' of the latching type, cam means comprising, in the specific embodiment herein described by way of example, a rotatable discoid element carrying on its peripheral portion adjustably positioned identical dog members, each having an axial projection so disposed that the action of each of said dog members with respect to either opening or closing said control means depends solely upon the axial I sense in which said projection'is extended. It is further proposed so to conform and dispose each of said dog members with respect to the discoid element by which it is carried that it may be set to become operative at any point through the whole circumference thereof, thus rendering the time setting of each event controlled thereby subject to infinitely precise adjustment.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which:

Fig. 1 is a perspective View of a portion of a time cycle controller incorporating the principles of the invention.

Fig. 2 is a fragmentary end elevation of a' her I I upon which is suitably mounted a control valve I2, which may expediently be of the type set forth and disclosed in U. S. Letters Patent No. 1,890,494, granted to P. A. Borden December 12, 1932, and including a stem having two extreme positions, and adapted to actuation to either of said positions by means of a tappet element pres- 'ently tobe described, Alternatively to the valve 12 there may be mounted a control element in the form of an electric switch, for example of the type exemplified in the U. S. Letters Patent,-

No. 1,960,020, granted to P. K. McGall, May 22;

1934. In fact said valve may be replaced by any" form of control device adapted to actuation. to either of two significant positions by means of limited excursion of a juxtaposed tappet member.

Secured to the base-plate I is a, further bracket member I3, extending forwardly from said base plate, and adapted to provide bearings for a tap- V pet arrn I4 and a latch member I5. The t'appet arm I4 carrying a vertically, adjustable tappet scr'e'w- I6, is journalle'd to said bracket member litatfa point near the base plate It and is adapted forv limited angular displacement about an axis,

whereby said screw will engage theste'm n of the valve I 2 and with displacement of said tappet will actuate said valve in a'generally vertical senseji'ri accordance with the displaced position ofj-saidt arm. A downwardly extending portion of's'aid t appet arm is formed into a cam follower part I8 having an inclined surface adapted to operative engagement by actuating means herein'a'fter'to be set forth. A- horizontally extending p'o'rtion of -said tappet arm is formed into a rest or stop I9" adapted for engagement by the latch member I5 journalled toward the outward exuemity'or the bracket I3, Ifo be'supported thereby in ,its uppermost operating position. The latch member I5 isprovided with a downwardly extending portion 28 conformed to function as a trigge'r or cam'follower; similar to the-cam folwear I 8 and similarly adapted for operative engagementi The relation between the tappet arm'- Ic' and-the latch I5 is madesuchthat When the former; has been lifted to its uppermost setting, asshowriin Fig; 1- of the drawings, thelatc'h I5,

impelled bygravity (or, ifdesired, by sprin mea'ris no'e shown in the drawing), will assume whole of the tappet' ariii It in said setting. Under" thisconditiomthe cam follow'erportion I8 of the tappet arm l l will 'rest mat'erially'higher in oleva'ti'on than the corresponding" part "of the latch" mem er It; bein'g lifted'to its uppermost position, the rest I9" will a e released; allowing, the tappet It to 'fall to its lowest setting, actuating the valve I2 in a sense opnpsae to that corresponding to its forineicondition. While, with the tappet arm I #dbi'SsGdf the position of the latch I 5* becomes of no significan'cathe juxtaposedfaces' of the tained in its highest position. Thus engagement of the eaindoliower' Hf] by suitablemeans will cause the. valve" I2 to bea'ctuated in-one sense (i. 'ei opened), and to remain so, until actuation of the cam follower 20 by other'and similar means. willcause said valve tofbe actuated in the opposite sense (i;' 8'. closed).

The cam mechanism for actuating the control element I 2"throu gh the agency; of the 'tappet arm-1 la'ndth' latch I5, and to which the present invention is specifically directed, will now be" described. Ashaft 25, whichmay" be supported Upon the" cairn renown 20 "thereby in a direction as indicated by the arrow a discoid member 26 formed preferably of metal; and having a flat central portion 21 and acontinuous rim portion 28 of generally toroidal conformation but with a flattened peripheral surface- 21- of cylindrical curvature.

Adapted to be adustably mounted upon the rimpor'tiOnZ'S in clamping relationship are identical c dogs 30, the number of these provided depending upon the number of events in the cycle to be controlled, and thesame .areconstructed as followsrA O-shaped base portion 3|, Figs. 3 and 5, is formed of stiff material, such as stainless:

steel; and is conformed to a cylindrical curvature corresponding to that of the section of theto'- roidal rim 28; to embrace the same. Secured; as

byweldin'g, to the base portion (H, and integral therewith, is a fingeror tappet-en'gaging pait'32 projecting tangentially to'the curved sul'f ace off, said base'portion, and in one direction only, substantially perpendicular to a radius thereof. A set screw 33, threaded through the material of the basepart 3!, serves, when said base part i s mounted upon the rim 28, to engage the flattened peripheral surface 29, producing a clamp ing action, whereby said dog may be secured at; any clesiredposition about the toroidal periphery of the discoid member 23.

In order that dogs may be placed upon, or rem'ovedfrom, the rim 28; there isprovided aisingle opening orwindo'w 35, perforated in part through the, flat central portion 21, and in part out through the contiguous inner face-of the rim portion'Z'B'. The length and width of saidwindow ares'uch as to'allow' a portion of the base part 3|" andf attaclied'portion of the fingerpart 32t'obe' passed through the window; and the radial positionofsaid'wi'ri'dow, with respect to the rim'iplortio'hiZB is such that when the dog- 35 s turned onits side: with the fingerpartjfleXter'ided radii any," the opens'ide of chocshaped base a ts-1* will just'pass the flats o'nthe toroidal riiri to al low the latter to be embracediby the former. This relationship will b'e" made clear by inspection and comparison of Figs. 4 and '.5.' Orioefplaced' upon" thiim'in this manner, the dog may be rotated. about; the axiso'f the rim through'an angle of degrees into its normal operating pos'itiori as" indicatedinFig". 3, and slidalong the riin' 2i f'to' be 'clairrr'id in any'des'ired' circumferential, loca tiorith'ereon byfmeaiis'of the set screw 33L Y It will be -observed that a dogjiiflf'ma'y' bejplace'd upon the rir'n'of the cani'in'either of twoop'elf ative" pds'ition's, viz., with. the finger part 32 "di;

rected were either the right-hand or the '1ertjhand emu of' the snare 2 5, whereby to w re 1 respectively either thftappet aiin' I3 'oiftlie' latch I5. Itwill' be apparent that, while in Fig; 1 reur actuating apes are shown assembled on t e 'c'anif, it i's'possible to utilize a ereateror a"les'sr'number asiocca'si rimay demand.

a merri at enin -c itmet anism, comprising a movable. supporting elei'rienft having, a. portion of substantially uniform thick ness surmounted by an expanded toroidal rim portion with flattened peripheral surface of cylindrical curvature; means slidably mounted over the expanded portion for adjustment along the same, and having a tappet-engaging finger projecting in its adjusted location laterally therefrom; and clamping means to secure against displacement in its adjusted location said slidably mounted means to the expanded rim portion of the movable element.

2. The cam member claimed in claim 1, wherein the supporting element is flat, and the tappetengaging finger is movable therewith in a plane parallel to said supporting element.

3. The cam member claimed in claim 1, wherein the tappet-engaging finger overhangs the supporting element.

4. The cam member claimed in claim 1, wherein a plurality of tappet-engaging fingers are carried by the movable supporting element and overhang the same on opposite sides thereof.

5. The cam member claimed in claim 1, wherein the supporting element is a rotatable, discoid plate.

6. The cam member claimed in claim 1, wherein the supporting element is a rotatable, discoid member, and the tappet-engaging finger overhangs the same and extends parallel to the axis of rotation of said discoid member to rotate therewith in a plane parallel to said discoid memher.

'7. The cam member claimed in claim 1, wherein the slidably mounted means is C-shaped, and is conformed to and adapted to encircle the toroidal expanded rim portion over more than half its contour.

8. The cam member claimed in claim 1, wherein the slidably mounted means is c-shaped and is conformed to and adapted to encircle the toroidal expanded rim portion over more than half its contour, and a tappet-engaging finger projects tangentially therefrom opposite its opening.

9. The cam member claimed in claim 1, wherein a set screw passes through the slidably mounted means to bear against the flattened peripheral surface of the supporting element to hold a tappet-engaging means in its adjusted position thereto.

10. The cam member claimed in claim 1, wherein the slidably mounted means is O-shaped, and is conformed to and adapted to encircle the toroidal expanded rim portion over more than half its contour, and an opening is provided through the supporting element adjacent the expanded rim portion and through a contiguous portion of the latter to pass said C-shaped means in a position at right angles to its tappet-actuating position.

11. A cam member for actuating tappet mechanism, comprising a fiat plate part movable in a sense parallel to a plane of its surface, and

having an expanded rim portion of cross-section substantially circular and of a diameter greater thanthe thickness of said plate and with a flattened outer edge part; and tappet-actuating means comprising a C-shaped member adapted to embrace said rim, encirclingmore than half the contour of said section, means for clampingly engaging said flattened edge part to secure said C-shaped member against displacement with respect to said rim portion, and a laterally projecting tappet-engaging finger.

12. A cam member for actuating tappet mechanism comprising a circular element having a rim portion of substantially toroidal conformation with a flattened peripheral surface of cylindrical curvature; and tappet-actuating means comprising a. C-shaped member adapted to embrace said rim portion encircling more than half the contour of its section, means for clampingly engaging said flattened peripheral surface to secure said member against displacement with respect to said rim portion, and a laterally projecting tappet-engaging finger, said circular element being provided with a window-like opening adjacent the inner edge of said rim portion and a contiguous portion of the latter to an extent to permit said C-shaped member, after being rotated through an angle about its axis of curvature, to be passed with one curved extremity through said opening and the other curved extremity over the flattened outer peripheral surface of said rim portion for subsequent rotation to its normal operating position to embrace said rimportion and be clamped thereto.

13. A cam member for actuating tappet mechanism, comprising a fiat plate part movable in a plane parallel to its surface, and having an expanded rim portion of cross-section substantially circular and of a diameter greater than the thickness of said plate and with a flattened outer dge part; and tappet-actuating means comprising a plurality of identical C-shaped members each adapted to embrace the rim, encircling more than half of said section, having a laterally projecting tappet-engaging finger, and means for clampingly engaging said flattened edge part to secure said C-shaped members against displacement with respect to said rim portion, each of said. members being adapted to be clamped with its,

laterally projecting finger extended on either side of the plate part to engage a corresponding one of a pair of cam-follower members,

ALVIN CHASE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS